Method to improve capacity in a communication network

Abstract

 Method to improve capacity in a communication network, comprising:
(i) a first process that runs on the coverage layer sending the users that are near the base stations to capacity layers; and
(ii) a second process in the capacity cell that managed the CPICH power periodically.
The method will enable networks to increase its capacity in 2^nd and 3^rd carriers by adjusting the CPICH power to the real needs.

Description

Object of the invention.

[0001] The present invention relates to a method to optimize the power allocated in CPICH Channel at capacity layers (2^nd and 3^rd frequency carriers) in order to have the maximum power available in the power amplifier for dedicated channels at any time (maximize capacity).

Field of the invention.

[0002] The present invention is specifically applicable to so-called "third-generation" system such as the UMTS terrestrial radio access network (UTRAN). The invention is also applicable to services like "wireless ADSL".

Background of the invention.

[0003] Power is one of the most valuable resources in 3G technologies so telecommunications operators need efficient process that let them to manage the power in an efficiency way. The most common implementation of power allocation for CPICH (Common Pilot Channel) is a static one. In those implementations it is reserved a certain amount of power for one channel that can not be used for any other purpose so this implementation in capacity cells is quite inefficient because that power is needed for dedicated channels more than for common channels.

[0004] A static resources management is always more inefficient than a dynamic strategy that take into account the cell conditions in terms of traffic load and users position. These two terms are used because the CPICH channel is the reference channel used by handset to estimate radio propagation conditions so at the end the amount of power allocated in the CPICH channel will represent a trade off between coverage and capacity.

[0005] Mobile operators need a dynamic power allocation method for CPICH channel that manage the power in the most efficient way in capacity cells with the aim to allocated as much power as possible in dedicated channel rather than in common channels.

[0006] The W02005032009 application describes a method for dynamically allocating power of a pilot channel. In this application, the CPICH modification is in the same layer. In this document it is not described the concept of multi carrier for managing user traffic. In the present invention it is related a method to dynamically tune the CPICH power in capacity layers taking into account there is a coverage layer. The application is based on traffic, but the aim is to balance the traffic between different neighbouring cells through different CPICH power. In the present invention, the CPICH is dynamically adjusted in all the cells of the cluster to maximize the coverage of all the cells.

[0007] The W003107703 application describes a cellular mobile telephone network and a procedure to optimize it. The aim of said patent is tune the CPICH power in order to mainly achieve a coverage area and use other carriers for capacity purpose. Said application does not describe the user location or power available for dedicated channels to tune the CPICH power dynamically. The solution proposed is static, because propose to use high CPICH power for coverage areas and low for capacity as the best way to use all the operators carriers mainly in roll out network phases. The present invention proposes CPICH dynamic changes based on traffic.

[0008] The WO03079574 application describes a method for configuring the power output of the pilot channels in a cellular radio network. Said application shows a method to calculate optimum CPICH power of a group of cells in the same frequency, taking into account the radio electrical environment, traffic load and site location. The main difference with the present invention is that the present invention modifies dynamically the CPICH power of different carriers.

[0009] The US6188906 application describes a method for coverage optimization of multifrequency assignment system, wherein reach the balance of traffic between different frequencies. The present invention of CPICH capacity tends to maximize the capacity reducing the power consumed by the common channels. in the capacity layer, but there is no traffic balancing between different frequencies.

Description of the invention.

[0010] In order to avoid the problems aforementioned, it is presented the method to improve capacity in a communication network, object of the present invention.

[0011] For 2nd or 3rd carriers, most of the available power could be devoted to capacity by reducing the CPICH (e.g. forcing near to the Base Station customers to roam/handover to the 2nd carrier). In this case the customers at the coverage cell border would not be affected as CPICH would be lowered, hence interference reduced. The practical implementation of this could be either static or dynamic, taking into consideration the customers under good/bad Ec/lo conditions, and adjusting this 2nd carrier CPICH accordingly.

[0012] The CPICH power adjustment method depend on the traffic load of the cell, if it is carrying a lot of traffic then it is needed extra power for dedicated channels and consequently it has to be necessary to reduce power in common channels, but it must be take into account the user's position in the cell, if the user are close to the base station it is possible to reduce the pilot channel without impact in service. There is a first process that runs on the coverage layer with the aim to send users near the base stations to capacity layers and a second process in the capacity cell that managed the CPICH power periodically.

[0013] The method to improve capacity in a communication network comprises, at least:

(i) a first process that runs on the coverage layer (first frequency) sending the users that are near the base stations to capacity layers; and

(ii) a second process in the capacity cell (2^nd and or 3^rd frequencies) that managed the CPICH power periodically.

[0014] Said first process comprising:

(a) a first step of establishing if there is available power in the coverage layer process less than power limit (threshold fix by the operator): if yes, then go to second step; if not, then go to end first process;

(b) a second step of establishing if RSCP of user is more than RSCP limit: if yes, then go to third step (it's close to the base station); if not, then go to end first process;

(c) a third step of HO (Handover) process for user from coverage layer to capacity layer, then go to end first process.

[0015] Said second process comprising:

(a) a first step of establishing if user % in good radio conditions (close to the node B) is more than threshold: if yes, then go to second step; if not, then go to third step;

(b) a second step of establishing if there is available power in the capacity layer process less than a first power limit: if yes, then go to reduce the CPICH in a step fix by the operator; if not, then go to end the second process (enough power available for capacity channels in the power amplifier);

(c) a third step of establishing if there is available power in the capacity layer process more than a second power limit and the users are far away from the node B : if yes, then go to fourth step; if not, then go to end the second process;

(d) a fourth step of establishing if CPICH power is less than CPICH power maximum: if yes then go to increase CPICH by a step; if not, then go to end the second process because you exceed the maximum CPICH power allowed by the operator;

(e) all the thresholds are tuned by the mobile operator and the two different Power limits in the second process are used for hysteresis purposes..

[0016] The method above described will enable networks to increase its capacity in 2^nd and 3^rd carriers by adjusting the CPICH power to the real needs.

Brief description of the drawings.

[0017] Following, it is briefly described some figures that helps to better understand the invention. The figures also describe an embodiment of the present invention, as non-limitative example:

• The figure 1 shows a diagram of the method object of the present invention.

Preferred embodiment of the invention.

[0018] Method to improve capacity in a communication network, object of the present invention, as it is shown in the figure 1. The method comprising:

(i) a first process that runs on the coverage layer sending the users that are near the base stations to the capacity layers; and

(ii) a second process in the capacity layer that managed the CPICH power periodically;

[0019] Said first process comprising:

(a) a first step of establishing if there is available power in the mobility layer process less than power limit: if yes, then go to second step; if not, then go to end first process;

(b) a second step of establishing if RSCP of user is more than RSCP limit: if yes, then go to third step; if not, then go to end first process;

(c) a third step of HO process for user from mobility layer to capacity layer, then go to end first process; and

[0020] Said second process comprising:

(a) a first step of establishing if user % in good radio conditions is more than threshold: if yes, then go to second step; if not, then go to third step;

(b) a second step of establishing if there is available power in the capacity layer process less than a first power limit: if yes, then go to reduce the CPICH; if not, then go to end the second process;

(c) a third step of establishing if there is available power in the capacity layer process more than a second power limit: if yes, then go to fourth step; if not, then go to end the second process;

(d) a fourth step of establishing if CPICH power is less than CPICH power maximum: if yes then go to increase CPICH; if not, then go to end the second process.

Claims

1. Method to improve capacity in a communication network, characterized in that it comprises:

(i) a first process that runs on the coverage layer sending the users that are near the base stations to the capacity layers; and

(ii) a second process in the capacity cell that managed the CPICH power periodically.

2. Method to improve capacity in a communication network of claim 1, characterized in that said first process comprising:

(a) a first step of establishing if there is available power in the mobility layer process less than power limit: if yes, then go to second step; if not, then go to end first process;

(b) a second step of establishing if RSCP of user is more than RSCP limit: if yes, then go to third step; if not, then go to end first process;

(c) a third step of HO process for user from mobility layer to capacity layer, then go to end first process;

3. Method to improve capacity in a communication network of claim 1, characterized in that said second process comprising:

(a) a first step of establishing if user % in good radio conditions is more than threshold: if yes, then go to second step; if not, then go to third step;

(b) a second step of establishing if there is available power in the capacity layer process less than a first power limit: if yes, then go to reduce the CPICH; if not, then go to end the second process;

(c) a third step of establishing if there is available power in the capacity layer process more than a second power limit: if yes, then go to fourth step; if not, then go to end the second process;

(d) a fourth step of establishing if CPICH power is less than CPICH power maximum: if yes then go to increase CPICH; if not, then go to end the second process.

Drawing